Architecture

Kehto is an early runtime implementation for NIP-5D napplets. It separates napplet hosting into small packages with clear ownership boundaries.

Alpha status: NIP-5D is still under development, and NAP contracts are not final. This architecture describes Kehto's current implementation, not a requirement that all napplet runtimes follow the same shape.

Layer	Package	Responsibility
Capability state	@kehto/acl	Pure access-control state and capability mapping.
Protocol engine	@kehto/runtime	Dispatch, service routing, ACL checks, storage, manifest/session state.
Browser shell	@kehto/shell	iframe/session lifecycle, postMessage, gateway loading, hosted supports(), browser registries.
Services	@kehto/services	Reference service handlers registered with the runtime.
Optional utilities	@kehto/nip, @kehto/wm	Unique Nostr NIP utilities, including NIP-5A/5D artifact verification/cache helpers, and shell-owned window-management contracts.

@napplet packages define portable napplet-side contracts and helpers. Kehto implements one host-side runtime and shell behavior.